How to design a simple condenser

[waisk]

I am a student which involves in a project which needed to build a refrigeration system, and the part that I am responsible to, is design an air cooled condenser which do not have a fan to cool it, because the system is an outdoor unit, so we plan to use natural wind to cool it, and I do not have any clue on how to start.. can anyone guide me?

And is it possible if I just asked the manufacturer of copper finned tube to bent the 6.5m tube in a coil shape and use it as a condenser?

[oldesky]

I am a student which involves in a project which needed to build a refrigeration system, and the part that I am responsible to, is design an air cooled condenser which do not have a fan to cool it, because the system is an outdoor unit, so we plan to use natural wind to cool it, and I do not have any clue on how to start.. can anyone guide me?

And is it possible if I just asked the manufacturer of copper finned tube to bent the 6.5m tube in a coil shape and use it as a condenser?

You will need to speak to a manfacturer/ wholesaler and provide him with the total heat of rejection* If you dont know this, the unit model, refrigerant, ambient temperature the condenser will operate in,the expected minimum wind velocity over the condenser and the application so the THR*and condenser size can be calculated.

[waisk]

The refrigerant will be using R134a, ambient temperature will be around 20c and minimum wind velocity will be 0.. This is because when there is wind, the system will only then generate, will be using the wind turbine to drive the compressors.. and the minimum wind speed when the compressor can work is 3m/s..

[waisk]

The refrigerant will be using R134a, ambient temperature will be around 20c and minimum wind velocity will be 0.. This is because when there is wind, the system will only then generate, will be using the wind turbine to drive the compressors.. and the minimum wind speed when the compressor can work is 3m/s..

[Yuri B.]

Hello Waisk.
Water is better. I would stake on the power of ocean(s) in your coutry-continent surrounded by them - from compressors powering to the whole refrigeration cycle.

[US Iceman]

...design an air cooled condenser which do not have a fan to cool it...

What you are describing is called a static condenser. This is an air-cooled condenser that operates without a fan. These types of condenser also do not normally have fins attached to the condenser tubing.

They operate on convective air currents only. Hot air rises and pulls cooler air behind the warm air flow upwards.

If this is for an engineering class you need to do some calculations on establishing convection air currents induced by the temperature differential achieved between the design condensing temperature and the ambient air.

If this is for a shop class you might try to find an old refrigerator that has a similar type of condenser and scale it up. Measure the condenser tubing length, height, width, etc. Next...try to find the compressor size.

Use the above to proportion the new condenser from what the old one is.

[waisk]

These types of condenser also do not normally have fins attached to the condenser tubing.

If this is for an engineering class you need to do some calculations on establishing convection air currents induced by the temperature differential achieved between the design condensing temperature and the ambient air.

If this is for a shop class you might try to find an old refrigerator that has a similar type of condenser and scale it up. Measure the condenser tubing length, height, width, etc. Next...try to find the compressor size.

Ya, this condenser do not have fins, but will it be fined if I use finned tube? And how to calculate the convection air currents? And what is actually mean by convection air currents? The ambient air as I know will be around 18 degree celcious.

[US Iceman]

And how to calculate the convection air currents? And what is actually mean by convection air currents?

Are you an engineering college student or going to a technical school?

Finned tubing could help reduce the size of the condenser, however, the fins can also accumulate dust and dirt too, which reduces the heat transfer rate.

Try looking for convection heat transfer on Google.

[waisk]

Are you an engineering college student or going to a technical school?

Oh.. I am an engineering student, and doing a final year project which is similar to a refrigeration system. The project is using the mechanical power of the wind turbine to power up the compressor. The compressor that we are using is taken out from a car. So, I planned to use the finned tubing to stimulate the condenser. But I am not sure the total length of the tubing that I needed to use, and also the size of the tubing as well.

I have searched about the convection heat transfer from the google. And slightly know what is that mean, and for my case, it is natural convection, and you mentioned that calculate the convection air current, is that mean the Rayleigh number?

[RefrigNoob]

Oh.. I am an engineering student, and doing a final year project which is similar to a refrigeration system. The project is using the mechanical power of the wind turbine to power up the compressor. The compressor that we are using is taken out from a car. So, I planned to use the finned tubing to stimulate the condenser. But I am not sure the total length of the tubing that I needed to use, and also the size of the tubing as well.

I have searched about the convection heat transfer from the google. And slightly know what is that mean, and for my case, it is natural convection, and you mentioned that calculate the convection air current, is that mean the Rayleigh number?

Check the rear of any fridge or freezer in your house. It has that black pipe that feels hot, at the back of the unit. It's usually inter connected with thin wire.
That's the condenser you want to build.
If you take some temperature readings and have a look at the convection airflow across it, it's a good place to start. You may even get kw readings and compressor sizes etc.
It's a place to start from.

[D.D.KORANNE]

First calculate thr as follows :

Refrigeration load + motor kw at design condition + 20% for pull down

and you can get a condenser from yr mkt

[waisk]

Check the rear of any fridge or freezer in your house. It has that black pipe that feels hot, at the back of the unit. It's usually inter connected with thin wire.
That's the condenser you want to build.
If you take some temperature readings and have a look at the convection airflow across it, it's a good place to start. You may even get kw readings and compressor sizes etc.
It's a place to start from.

I know how the refrigerator condenser look like after I searched the image from google. But how to have a look at the convection airflow? And the compressor that we have is from a car, and as I know the car condenserhave a lot of fin and also a fan in it. So, how do I actually need to modify my condenser? The compressor have a power rating of 1kw.

[waisk]

First calculate thr as follows :

Refrigeration load + motor kw at design condition + 20% for pull down

and you can get a condenser from yr mkt

How can I get the refrigeration load? The refrigerant that we used is R134a. And the motor kw at design condition is around 1kw.

[D.D.KORANNE]

Product load + lossess etc put together will be your cooling load